S,S-dialkyl-o-and s-alkenyl phosphites and phosphates

ABSTRACT

Phosphoric acid esters of the formula   WHEREIN X denotes oxygen or sulphur, the integer n is the number 0 or 1, R&#39;&#39; and R&#39;&#39;&#39;&#39; independently of each other represent an alkyl radical with 3 to 5 carbon atoms and wherein A. IF X is oxygen, R represents an alkoxyalkylene, alkylmercaptoalkylene or alkenyloxyalkylene radical with at most 7 carbon atoms, an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which is substituted by halogen, methyl and/or methoxy, or wherein B. IF X is sulphur, R represents an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group substituted by halogen, methyl and/or methoxy; these compounds are useful for defoliating and promoting the ripening of crop plants especially cotton.

United States Patent [191 Beriger et al.

[54] S, S-DIALKYL-O-AND S-ALKENYL PHOSPHITES AND PHOSPHATES Related U.S. Application Data [62] Division of Ser. No. 105,125, Jan. 8, 1971, Pat. No.

[30] Foreign Application Priority Data Jan. 16, 1970 Switzerland 595/70 [56] References Cited UNITED STATES PATENTS 3/1952 Oberright 260/956 X 3/1963 Vegter et al. 260/956 X Primary Examiner-Anton H. Sutto Attorney, Agent, or Firm-Frederick H. Rabin [451 May 20, 1975 [57] ABSTRACT Phosphoric acid esters of the formula wherein X denotes oxygen or sulphur, the integer n is the number 0 or I, R and R" independently of each other represent an alkyl radical with 3 to 5 carbon atoms and wherein a. if X is oxygen, R represents an alkoxyalkylene, alkylmercaptoalkylene or alkenyloxyalkylene radical with at most 7 carbon'atoms, an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which is substituted by halogen, methyl and/or Inethoxy, or wherein b. if X is sulphur, R represents an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group substituted by halogen, methyl and/or methoxy; these compounds are useful for defoliating and promoting the ripening of crop plants especially cotton.

4 Claims, No Drawings S. S.-DIALKYL-O-AND S-ALKENYL PHOSPHITES AND PHOSPHATES wherein X denotes oxygen or sulphur, the integer n is the number or 1, and R and R" independently of each other represent an alkyl radical with 3 to carbon atoms, and wherein I a. if X is oxygen, R represents a branched or unbranched alkoxyalkylene, alkylmercaptoalkylene or alkenyloxyalkylene radical with at most 7 carbon atoms, an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which atoms, and X denotes oxygen or sulphur; also, the compounds of the formula wherein R represents an alkyl group with l to 3 carbon atoms, R represents an alkylene groupwith "2 to 4 carbon atoms, R and R independently of e achlother rep resent an alkyl, radical with 3 to 5 carbon atoms and the integer n is the number 0 or- 1; in addition, the coin-6 pounds of the formula wherein X denotes oxygen or sulphur and-R represents f an unsubstituted benzyl group or abenzyl group which is optionally substituted by halogen methyl or methoxy or wherein Xdenotes oxygen, R is an alkenyl group is optionally substituted by -halogen, methyl and/or methoxy, or wherein b. if X is sulphur, R represents, an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which is optionally substituted by halogen, methyl and/or methoxy.

Among the phosphites and phosphates of formula I are certain groups possessing a particularly lasting biological activity, for example the compounds of the formula R O-R -O-P (II) wherein R represents an alkyl group with l to 3 carbon atoms, an alkenyl group with 3 to ,6 carbon atoms, R represents an alkylene group with 2 to 4 carbon atoms, R and R independently of each other represent an alkyl radical with 3 to 5 carbon atoms and the integer n is the number 0 or 1; furthermore, the compounds of the formula or ll R 3 wherein R represents an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which is optionally substituted by halogen methyl or methoxy and R and R independently of each other represent an alkyl group with 3 to 5 carbon chlorine, bromine and iodine with 3 to 6 carbon atoms, and R and R independently of each other representan alkyl radical with 3 to 5 car: bon atoms. I t C In the formulae I to V, the substitu'ents Rf, R-,','.R

and R4 preferably denote an n-propyl orrfbutyl radi- I cal.

In the formulae I, III and V, the term halogen denotes In US. Pat. No. 2,955,803, mom, phosphites which are substituted by hydrogen, lower alkyl and/or aryl, have'already beendescrib'ed as defo-.

. liants for crop pIants The commercially 'available' tri-j (n-butyl)-trithiophosphite is Well known, the activity of which is not satisfactory in practical application.

Furthermore, mono-, diand trithiophosphates, preferably those with lower alkyl radicals,"are described in U.S. Pat. No. 2,965,467 as defoliants, of which tri-(nbutyl)-trithiophosphate,hasbecome known as a ccommercial product. It also possesses deficient activity, especially inthe defoliation of cotton plants.

' With neither of the two commercial products is a sat- I isfactory defoliation achieved or the growth of new leaves permanently suppressed. The activity is not improved by increased dosage.

Compared with these preparations, the group of compounds characterized by formula I exhibits considerable advantages, as the biological Examples detailed later on show. t

In the case of plants that shed their leaves annually', abscission can be induced at any time desired by using compounds of formula I by themselves, or appropri-. I, ately in the form of agentsQIf plants, especially crop plants such as cotton, soybean, fruit-bearing trees, or

ornamental plants are treated in this way, abscission occurs as a rule within 3 to 6 days. In general, ripening is thereby promoted simultaneously.

Favorable rates of application for active substances of formula I are in the order of l to 6 kg per hectare. It must, however, be taken into consideration here that degree of ripening, stage of development, climate,

weather, nature of the soil and other influences, will up and trithio- I suggest, if necessary, rather higher or lower rates of application.

The compositions according to the invention containing preferably 1-80 percent by weight of active substance can be applied in diverse ways, for example in the form of dusts, aqueous dispersions. aqueous emulsions, granules and so forth. They also contain as a rule one or more solid or liquid carriers or extenders. By extenders are to be understood solid or liquid diluents.

The compounds of formula I can be applied to the plants in inert media,jfor example as a dust, mixed with a pulverulent, mineral carrier (for example mica, talc, pyrophyllite, clay) or they can be sprayed in aqueous form.

The agents are preferably also used mixed with small amounts of an anionic, cationic or non-ionic surfactant. Such an additive assists the dispersions of the compounds of formula I in water. The compounds can also be mixed with pulverulent carriers, such as mineral silicates', toge ther with a small amount of a surface-active ,dispersin'g agent, in such a way that an easily wettable n powder isjobtained that can be applied directly to the plantsoi' can be shaken with water in order to manufactui'e,quickly a suspension of the chemical compound and of the pulverulent carrier in water.

' The anionic surface-active substances which can be used with the present compounds or agents which influen'ce 'plant'growth correspond to the general formula R COOM or,RSO M. Herein M represents an alkali metal, an ammonium radical or a substituted ammonium or amine radical and R represents an organic rad- ,ical. which contains at least one group with more than 7. Sulphonated glycol-esters with long chains of fatty acids, for example 8. Sulphonated alkyl-substituted amides of fatty acids with a long chain 9. Alkylated arylsulphonates, for example sodium isopropylnaphthalenesulphonate and dodecylbenzenesulphonate.

l0. l-lydroaromatic sulphonates, for example tetrahydronaphthalenesulphonate.

1 l. Alkylsulphosuccinates, for example sodium dioctylsulphosuccinate.

l2. Arylsulphonate-formaldehyde condensation products, for example the condensation product of formaldehyde and sodium naphthalenesulphonate:

sodium I 1 a0 Na I on,

wherein n is 10 to 20.

3. Partial esters of polyhydric alcohols with fatty acids having a long chain, for example diethylene glycol monolaurate and sorbitane trioleate.

Cationic surface-active components which can be used for the plant-influencing active substances according to the invention are, for example, the followl. Quaternary ammonium salts, in which one of the groups bonded to the nitrogen is an aliphatic group with at least 8 carbon atoms, for example trimethylcetylammonium iodide, laurylpyridinium chloride, cetyldimethylbenzylammonium chloride and N-stearylbetaine.

2. Amines, amides, diamines and glyoxalidines which possess an aliphatic group which contains at least 8 carbon atoms, and their acid esters, for example stearylamine hydrochloride, oleylamide, diethylethylene-oleyldiamine and cu-heptadecyl-N- hydroxyethylglyoxalidine.

Furthermore, additional known defoliants, abscission accelerators or also growth regulators can be added to the active compounds of formula I in the practical application. Possible defoliants are, for example, tri-(nbutyl)-trithiophosphite (Folex), tri-(n-butyl)-trithiophosphate (DEF), or Na-cis-3-chloroacrylate (PREP). Known growth promoting substances that can be added to the compounds according to the invention are:

Mil)

ALANAP, DURASET, PHOSPHON, VERNOLEPIN, -fur'furylaminopurine, naphthylacetic acid, B-indolylbutyric acid, indolylacetic acid, fluorene-6-carboxylic acid and derivatives thereof, chlorocholine chloride,

'hydroxyethylhydrazine, cycloheximide, ascorbic acid,

succinic acid-dimethylhydrazide, maleic acid hydrazide, 2,3,5-triiodobenzoic acid.

Together with the compounds of formula I, a satisfactory abscission accelerator is especially disodium-3,6- endoxohexahyclrophthalate, which has become known under the name Endothall.

The new phosphites and phosphates of formula (I) R x P can be manufactured according to methods known per se by the stepwise replacement of the C1 atoms in PCI;, and POC1 by corresponding alcohols or thioalcohols;

v ,for example, by reacting a dichloride of the formula stepwise with a mercaptan of the formula R SH and with a mercaptan of the formula R" SH Active Substance No.

\i mm u preferably in the presence of a tertiary amine, in the process of whichthe reaction with the first mercaptan, incase R and R" are different, is carried. ou tappropri- (VII) In the following Examples, the parts are parts by weight.

EXAMPLE 1 17.7 Parts of methoxyethyldichlorophosphite are introduced into 100 parts by volume of benzene. Thereto is added dropwise at l0?20C under nitrogen a mixture of 18.2 parts of butylrne'rcaptan and 20 parts of triethylamine in 50 parts by volume of benzene. The mixture is stirred for 2 hours at ambient temperature. For

"processing, the benzene solution is shaken repeatedly ately in the absence of a tertiary amine ,lo'r by 'reacting a monochloride of the formula with water and the solvent thereafter evaporated in vacuo. 23.9 Parts of a colourless oil of the formula (:1i,oc,,n., o-P scni n 11,, 1.5061 (Active substance. No. 1)

are obtained as residue.

The following derivatives were manufactured analogously:

Formula 27 CH OC H OP(SC H n) n 1.514} V iso) EXAMPLE 2 19.3 Parts of methoxyethyldichlorophosphite are introduced into parts by volume of benzene. Thereto is added dropwise at l0-20C a mixture of 18 parts of butylmercaptan and 20.5 parts of triethylamine in 50 are obtained as residue.

Thefollowing phosphoric acid esters were manufactured analogously:

n3 1.4980 (Active substance No. 12)

8 r and 10.5 parts of triethylamine in 20 parts by volume of benzene are added dropw-iseat' 209-30C and the mixture stirred overnight at -an'lbieflt temperature. For

processing, the benzene solution is shaken repeatedly 5 with water and the solvent'thereafter evaporated in I vacuo. 25.2 Parts of a light yellow oil of formula (Active substance No. 20)

are obtained as residue.

The following esters can be manufactured in analogous manner:

Active Substance No. Formula I 9 m i 13 CH OC H OP(SC I-l sec) I n 1!. 4989' 20 14 I CH OCH C:} IOP(()SC H 1So) IIID 1. 4971 I I '7 3 n 4 214, 15 I cH ocH -cH-og(sc 1i n 1.4952

u 4 I 16 I H c 0(cH o wsc agn) In 1.4921 v 24. J 1 CH =CI1II-CH OCI; CH OPI(SC H9n) n 1.5010 I I n .21" I 18 IH C SCH CH O P(SC H n) I nD I I I I u y I 4 I I I 19 CH OCH CH OP(SC H n) I In I I 1.50;;

Active Substance No EXAMPLE 3 65 26 Partsof dibutyldithiochlorophosphate (b.p. 131C at 0.05 mm Hg) are introduced into 100 parts by volume of benzene. A mixture of 5.8 parts of allylalcohol "Formulai u' 5 4 9 'QEzQ I I inventionand precipitated silicic acid are finely I ground. By mixing with kaolin or talc, dusting agents containing for preference 1-6% content of active .substance are manufactured.

Spraying Powders n v To manufacture a spray ing powder, the following components, for example, are mixed and finely ground:

75 parts of active substance parts of highly adsorptive silicic acid 10 parts of bolus alba (kaolin) 3.5 parts of a reaction product from p-tert.octylphenol and ethylene oxide 1.5 parts of sodium-l-benzyl-2-stearyl-benzimidazolyl-6,3 '-disulphonate.

Emulsion Concentrate Active substances that are readily soluble can also be formulated according to the following prescription:

parts of active substance 70 parts of xylene 10 parts of a mixture from a reaction product of an alkylphenol with ethylene oxide and calcium dodecylbenzenesulphonate are mixed. On diluting with water to the desired concentration there results an emulsion that is capable of being sprayed.

EXAMPLE 5 Four month old cotton plants (with their capsules burst open) that have been raised in conditioning cabinets, were sprayed with concentrations of the various preparations containing 4 kg of active substance per hectare. Six days later, evaluation took place according to a grading system of 1 to 5, in which 1 denotes no defoliation and 5 denotes total defoliation,

The results are listed in the following table:

Active Substance N0. Defoliation aulutmmggulututmut EXAMPLE 6 Four month old cotton plants of the variety Delta Pine (approx. 1.20 m high) with 80-90% ripened,

opened capsules, were treated in lots of 10.8 m in Sou'th'Alfrica in April during hot, dry weather, with active substance concentrations of 2 kg a.s./ha and 4 kg a.s,./ hjaf. amount of water used was 820 liters per hectare. Tri-(n-butyl)-trithiophosphate (=Folex) was used as comparative substance. Three parallel tests were carried out per active substance and concentration. The leaves of all test plants were counted before the treatment and l and 2 weeks after the treatment.

The commercial preparation Folex (tri-(n-butyD-trithiophosphite), even if applied at excess dosage, is not able to exceed a threshold value of approx. 85% defoli-- ation. In contrast thereto, preparations according to the invention clearly show, at both concentrations, a better and permanent defoliation.

We claim:

l. A compound of the formula II n R x P (s nc H in which R is alkenyl of from 3 to 6 carbon atoms, X is oxygen or sulphur, and n is the number 0 or 1.

2. A compound according to claim 1 in which n is 1. 3. The compound according to claim 2 which is 4. A compound according to claim 1 in which X is oxygen, and n 0. i 

1. A COMPOUND OF THE FORMULA
 2. A compound according to claim 1 in which n is
 1. 3. The compound according to claim 2 which is
 4. A compound according to claim 1 in which X is oxygen, and n
 0. 